<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>媒体查询(侧边栏隐藏)</title>
    <style>
        body {
            display: flex;
            background-color: #dfdbdb;
            margin: 0;
            padding: 0;
            border: 0;
        }

        div {
            font-size: 60px;
            color: #fff;
            text-align: center;
            line-height: 100vh;
        }

        .left {
            width: 250px;
            height: 100vh;
            background-color: rgb(135, 192, 241);
        }

        .right {
            flex: 1;
            height: 100vh;
            background-color: rgb(109, 159, 253);
        }

        @media(max-width: 768px){
            .left {
                display: none;
            }
        }
    </style>
</head>
<body>
    <div class="left">left</div>
    <div class="right">right</div>
</body>
</html>